The animation starts by brief explanation of the virus replication cycle. It is covered under three main headings 1) Initiation of infection 2) Replication and the expression of the virus genome 3) Release of the mature virions from the infected cells.
There are eight stages of virus replication these are 1) Attachment 2) Penetration 3) Uncoating 4) Gene expression 5) Genome Replication 6) Assembly 7) Maturation 8) Release
Synthesis : The viral synthesis stage begins immediately after the process of uncoating- the process that exposes the viral nucleoprotein complex to the cellular environment. The synthesis stage leads to the massive production of viral components.
The viral genome synthesis involves two stage Genome expression and Genome replication. Genome replication is the production of viral genomes; Genome expression is the production of viral proteins. Genome expression is a multi-step process that includes transcription and translation.
The synthesis of all viruses involves transcription or generation of positive messenger RNAs (mRNAs) from their genomes and the use of host ribosome to translate the viral mRNA into viral proteins. However, the precise strategies employed to synthesize the mRNAs is different for different viruses.
The important stages in the synthesis of various viral genome syntheses are covered in detail in the animation:
- dsDNA(+/-) Class I
- ssDNA(+) dsDNA intermediate Class II
- dsRNA(+/-) Class III
- ssRNA(+) class IV
- ssRNA(-) class V
- ssRNA(+) DNA intermediate class VI
- dsDNA (+/-) RNA intermediate class VII
- How is mRNA synthesized?